Update documentation of java.util.Date class

A DESCRIPTION OF THE REQUEST :
Documentation states to visit, http://tycho.usno.navy.mil for more information. As per http://tycho.usno.navy.mil. It is now part of larger website http://www.usno.navy.mil.


JUSTIFICATION :
Making sure links are pointing to updated website

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Change link the documentation from http://tycho.usno.navy.mil to http://www.usno.navy.mil
and link related to definitions of "Systems of Time" from http://tycho.usno.navy.mil/systime.html to http://www.usno.navy.mil/USNO/time/master-clock/systems-of-time
ACTUAL -
Links are pointing a older website